TW201913907A - Film flip chip package structure - Google Patents

Abstract

A chip-on-film package structure includes a flexible substrate and a chip. The flexible substrate includes a flexible base having an upper surface and a lower surface opposite to each other, and a circuit layer. A chip mounting area having a first side and a second side opposite to each other is defined on the upper surface. The circuit layer includes a plurality of first upper leads, second upper leads, first vias and lower leads. The second upper leads are disposed in the chip mounting area, and each has a second inner end and an upper pad opposite to each other. The second upper leads are divided into a plurality of groups. The upper pads in each of the groups are arranged layer by layer into at least two rows from positions near the second inner ends towards the second side, and in the furthest row there are two upper pads symmetrically arranged in two sides of a reference line of each of the groups. The chip is mounted in the chip mounting area.

Description

Thin-film flip-chip packaging structure

The present invention relates to a chip packaging structure, and more particularly, to a thin-film flip-chip packaging structure.

With the improvement of semiconductor technology, liquid crystal displays have the advantages of low power consumption, light weight, high resolution, high color saturation, and long life. Therefore, they are widely used in mobile phones, notebook computers or desktop computers. LCD screens, LCD TVs and other electronic products that are closely related to life. Among them, the driver IC of the display is an indispensable and important component of the liquid crystal display. In response to the needs of various applications of liquid crystal display device driving chips, tape automatic bonding (TAB) packaging technology is generally used for chip packaging, and a chip-on-film (COF) packaging structure is one of the applications Packaging structure with automatic tape and reel technology.

With the increasing demand for electronic product functions, the density of integrated circuits on chips has continued to increase, and the number of pins on flexible circuit substrates of thin-film flip-chip packaging structures must also increase. The wiring of single-sided circuit flexible substrates, which are widely used in the past, is getting more and more difficult. Therefore, the flexible circuit substrates are designed to face double-sided circuits. At present, most of the pins on a flexible substrate of a double-sided circuit extend outward from the wafer bonding area on the upper surface of the flexible substrate, and then the circuit is guided to the lower part through conductive vias in the area outside the wafer bonding area. Surface pins. Generally speaking, the number of bumps on the output end of the driving chip is very large, and a large number of pins correspond to the bumps on the output end and extend from the wafer bonding area through the edge of the wafer to the outside of the flexible substrate. However, limited by the size of the chip, the width of the pins, and the spacing, the number of pins that can pass through is limited, making it difficult to increase the number of bumps at the output of the chip. In addition, the vias provided outside the wafer bonding area also occupy the area where the pins can be distributed, thereby reducing the degree of freedom of wiring on the flexible circuit substrate.

The invention provides a thin-film flip-chip packaging structure. The upper pads corresponding to the connection vias can be arranged in multiple rows, which can greatly increase the number of pins and effectively reduce the pitch of the pins.

A thin-film flip-chip packaging structure of the present invention includes a flexible circuit substrate and a wafer. The flexible circuit substrate includes a flexible substrate and a circuit layer. The flexible substrate has opposite upper and lower surfaces, the upper surface defines a wafer bonding area, and the wafer bonding area has a first side and a second side opposite to each other. The circuit layer includes a plurality of first upper pins, a plurality of second upper pins, a plurality of first vias, and a plurality of lower pins. A plurality of first upper pins and a plurality of second upper pins are located on the upper surface, and each of the first upper pins has a first internal connection end. These first internal connection ends are located in the wafer bonding area and are adjacent to the first side. The first upper pin extends from the first internal connection end in a direction away from the wafer bonding area. A plurality of second upper pins are disposed in the wafer bonding area, and each second upper pin has opposite second inner terminals and upper pads, and the second inner terminals are adjacent to the first side and are inferior to the first inner terminals. The end is far from the first side, and each second upper pin extends from the second internal end toward the second side to connect the upper pad. The width of each upper pad is larger than the width of the other parts of the second upper pin. These The second upper pins are divided into multiple groups, and the upper pads in each group are arranged in at least two rows layer by layer from the direction adjacent to the second internal end toward the second side, and are separated from the second internal end The furthest at least one row has at least two upper pads arranged symmetrically on both sides of the reference line of each group, wherein the reference line is adjacent to or overlaps the center line of each group. A plurality of first vias penetrates the flexible substrate and are located in the wafer bonding area. These first vias are respectively connected to the upper pads. A plurality of lower pins are located on the lower surface and are electrically connected to the second upper pins through the first vias. The wafer has a first side and a second side opposite to each other, and includes a plurality of first bumps and a plurality of second bumps near the first side. The wafer is disposed in a wafer bonding area. The first bumps are bonded to the first internal connection end, and the second bumps are bonded to the second internal connection end.

Based on the above, the thin-film flip-chip packaging structure of the present invention is configured by arranging a plurality of second upper pins having a second internal end and an upper pad in a chip bonding area, and the second upper pins are divided into multiple groups. A plurality of upper pads in each group are closely arranged layer-by-layer / row-by-row in a direction away from the second internal connection end to arrange more upper pads in a wafer bonding area of a limited size. Further, the upper pad and the lower pin are correspondingly connected through the first via hole, so that the flexible circuit board has a first upper pin extending outward from the upper surface of the flexible substrate, and also has chip bonding. The circuit extends to the second upper pin on the lower surface of the flexible substrate through the upper pad and the first via, and the second upper pin further extends outward through the lower pin. In this way, the number of pins that can be laid on the flexible circuit substrate can be greatly increased for chip connections with more bumps. Moreover, in the above configuration, since the upper pad and the second upper pin are in the wafer bonding area, the portion of the flexible substrate outside the wafer bonding area will not be occupied, and the wiring layer is on the flexible base. The layout on the wood can be more flexible.

In order to make the above features and advantages of the present invention more comprehensible, embodiments are hereinafter described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a thin-film flip-chip packaging structure according to an embodiment of the present invention. FIG. 2 is a partially enlarged schematic view of a circuit layer of the thin-film flip-chip packaging structure of FIG. 1. FIG. 3 is a schematic partial cross-sectional view of the thin-film flip-chip packaging structure of FIG. 1. It should be noted that the thin-film flip-chip package structure shown in FIG. 1 is only a schematic and simple illustration of and enlarges a set of second upper pins in the chip bonding area, and is for reference only. The actual number and size ratio Will not be similar to that shown in Figure 1. Similarly, the partial enlarged schematic diagram of the circuit layer shown in FIG. 2 is only a schematic simple drawing and enlargement of the two sets of the second upper pins, and the actual number and scale size will not be similar to those shown in FIG. 2.

Please refer to FIG. 1 first. The thin-film flip-chip packaging structure 10 of this embodiment includes a flexible circuit substrate 100 and a chip 170. The flexible circuit board 100 includes a flexible substrate 200 and a circuit layer 300. The flexible circuit board 100 is a double-sided circuit board.

Referring to FIGS. 1 and 3 at the same time, the flexible substrate 200 has an upper surface 106 and a lower surface 108 opposite to each other. The upper surface 106 of the flexible substrate 200 defines a wafer bonding region 110, and the wafer bonding region 110 has a first side 112 and a second side 114 opposite to each other. The circuit layer 300 includes a plurality of first upper pins 150, a plurality of second upper pins 152, a plurality of first via holes 160, a plurality of third upper pins 154, and a plurality of lower pins 156.

Please refer to FIG. 1 and FIG. 3 at the same time. In this embodiment, the flexible substrate 200 has a first end 102 and a second end 104 opposite to each other. The plurality of first upper pins 150 are located on the upper surface 106 of the flexible substrate 200, and each of the first upper pins 150 has a first internal connection end 122. The plurality of first internal connection ends 122 are located in the wafer bonding area 110 and are adjacent to the first edge 112. The plurality of first inner connecting ends 122 are successively arranged along a direction parallel to the first side 112. Each first upper pin 150 extends from each first internal connection end 122 toward the first end 102 in a direction away from the wafer bonding area 110.

The plurality of second upper pins 152 are located on the upper surface 106 of the flexible substrate 200 and are completely disposed in the wafer bonding area 110. Each second upper pin 152 has a second inner connecting end 127 and upper pads 133 and 135 opposite to each other. In detail, the plurality of second inscribed ends 127 are adjacent to the first side 112 and are farther from the first side 112 than the plurality of first inscribed ends 122. The plurality of second inner connecting ends 127 are successively arranged along a direction parallel to the first side 112. Each second upper pin 152 extends from the second inner end 127 toward the second side 114 and is connected to the upper pads 133 and 135. The plurality of upper pads 133 and 135 are respectively correspondingly connected to the plurality of first via holes 160. In order to match the size of the first via 160 and ensure that the upper pads 133 and 135 are connected to the first via 160, the width of each of the upper pads 133 and 135 will be larger than that of other portions of the second upper pin 152 (including the first The width of the two inner ends 127). In more detail, each second upper pin 152 extends from the second internal connection end 127 with a smaller width toward the second side 114 and connects the upper pads 133 and 135 with a larger width. If the upper pads 133 and 135 having a larger width are also successively arranged in a direction parallel to the first side 112, the pitch of the second inner end 127 will be increased, and the length of the first side 112 of the wafer bonding area 110 will be increased. In a fixed situation, the number of second upper pins 152 that can be laid out is bound to decrease, which is not conducive to the increase in the number of pins and the need for fine pitch. Therefore, the plurality of upper pads 133 and 135 are arranged layer by layer in at least two rows toward the second side 114.

Please refer to FIG. 1 and FIG. 2 at the same time. In this embodiment, the plurality of second upper pins 152 are divided into a plurality of groups G, and each group G is successively arranged along a direction parallel to the first side 112, and each group The plurality of second upper pins 152 in the group G are roughly separated by a reference line L into left and right sides, and the reference line L is adjacent to or overlaps the center line of each group G, where the center line of each group G is A line perpendicular to the first side 112 and extending through the center of each group G. In detail, please refer to FIG. 1 first. The thin-film flip-chip packaging structure 10 of FIG. 1 only schematically illustrates a second upper pin 152 of a group G in the wafer bonding region 110. A partially enlarged view of the flexible circuit substrate 100 in FIG. 2 also only schematically illustrates the second upper pins 152 of the two groups G. However, the number of the group G and the number of the second upper pins 152 of each group G of the present invention are not limited thereto.

In this embodiment, the plurality of upper pads 133 and 135 of the second upper pin 152 of each group G are arranged in at least two rows layer by layer from the direction adjacent to the second internal end 127 toward the second side 114. The at least one row furthest from the second inner end 127 has a plurality of upper pads 135 arranged symmetrically on both sides of the reference line L. In other words, the plurality of upper pads 133, 135 are arranged in at least two rows along the direction perpendicular to the first side 112 and toward the second side 114, and the row farthest from the second inner end 127 / the first side 112 The number of the upper pads 135 is at least two. The at least two upper pads 135 are arranged in a direction parallel to the second side 114 and are arranged symmetrically on both sides of the reference line L. In this embodiment, the reference line L overlaps the center line of each group G.

Please refer to FIG. 1 and FIG. 2. In this embodiment, the upper pads 133 and 135 of the second upper pin 152 of each group G are arranged in two rows in a direction away from the second inner terminal 127. The upper pads 133 adjacent to the second inner end 127 are in the innermost row R _i , and the upper pads 135 farthest from the second inner end 127 are in the outermost row R _o . However, the upper pads of the present invention The number of rows is not limited to this. In fact, the number of the second upper pins 152 and the number of rows of the upper pads 133 and 135 of each group G are based on the total number of the second upper pins 152, the size of the available space in the chip bonding area 110, and the upper pads. Acceptable minimum size of 133,135 for optimized layout. In detail, in this embodiment, the number of the upper pads 133 located in the innermost row R _i in each group G is two, and the number of the upper pads 135 located in the outermost row R _o is two, and two The upper pads 135 are symmetrical and disposed on both sides of the reference line L in a face-to-face manner. However, the present invention does not limit the number of the upper pads 133 and 135 in each row.

Please refer to FIG. 1, FIG. 2 and FIG. 3 at the same time. In the present embodiment, the plurality of first through holes 160 penetrate the flexible substrate 200 and are located in the wafer bonding region 110. In detail, the plurality of first via holes 160 are respectively connected to the plurality of upper pads 133 and 135 respectively. Referring to FIG. 3, the plurality of lower pins 156 are located on the lower surface 108 of the flexible substrate 200, and the plurality of lower pins 156 are electrically connected to the plurality of second upper pins 152 through the plurality of first vias 160.

Please continue to refer to FIG. 3. In this embodiment, each lower pin 156 has a lower contact pad 137, a plurality of lower contact pads 137 are respectively disposed corresponding to a plurality of upper contact pads 133 and 135, and a plurality of first through holes 160 A plurality of upper pads 133 and 135 and a plurality of lower pads 137 are connected correspondingly.

In this embodiment, each of the lower pins 156 extends outward from the lower pad 137. In detail, the plurality of lower pins 156 extend from the wafer bonding region 110 to the lower end 108 of the flexible substrate 200 toward the first end 102. In more detail, the positions of the plurality of lower pins 156 on the lower surface 108 of the flexible substrate 200 may respectively correspond to the plurality of first upper pins 150 extending in the direction of the first end 102 and located on the upper surface 106. s position. Thereby, the distribution of the metal circuits on the upper surface 106 and the lower surface 108 is more consistent, which can avoid the problem of poor bonding between the chip 170 and the pins caused by uneven force, and reduce the occurrence of warping of the flexible circuit substrate 100. . However, in other embodiments, the lower pin 156 may also extend in the direction of the second end 104.

Please refer to FIG. 1 and FIG. 3 again. In this embodiment, the chip 170 of the thin-film flip-chip package structure 10 has a first side 173 and a second side 174 opposite to each other. The wafer 170 includes a plurality of first bumps 175 and a plurality of second bumps 176 located on the active surface and close to the first side 173. The plurality of first bumps 175 and the plurality of second bumps 176 are respectively arranged in a single row. The method is arranged in a direction parallel to the first side 173, and the plurality of second bumps 176 are farther from the first side 173 than the plurality of first bumps 175. The wafer 170 is disposed in the wafer bonding region 110 in a flip-chip manner with the active surface facing the upper surface 106, wherein the first side 173 corresponds to the first side 112 of the wafer bonding region 110 and the second side 174 corresponds to the second side 114. As shown in FIG. 3, the plurality of first bumps 175 are respectively connected to the plurality of first inner joint ends 122, and the plurality of second bumps 176 are respectively connected to the plurality of second inner joint ends 127. In this embodiment, the plurality of first bumps 175 and the plurality of second bumps 176 are output terminal contacts, and the plurality of first upper pins 150 and the plurality of second upper pins 152 are output terminal pins. .

In this embodiment, the circuit layer 300 further includes a plurality of third upper pins 154 on the upper surface 106. Each third upper pin 154 has a third internal connection end 145, and a plurality of third internal connection ends 145 are located in the wafer bonding area 110 and are adjacent to the second side 114. The plurality of third inner connecting ends 145 are successively arranged along a direction parallel to the second side 114. As can be seen from FIG. 1, each of the third upper pins 154 extends from the third internal connection end 145 in a direction away from the wafer bonding region 110. In detail, the plurality of third upper pins 154 extend from the third internal connection end 145 toward the second end 104 or the first end 102. As can be seen from FIG. 3, the wafer 170 includes a plurality of third bumps 177 near the second side 174, and the plurality of third bumps 177 are arranged in a single row in a direction parallel to the second side 174, and a plurality of The three bumps 177 are respectively connected to the plurality of third inner ends 145. In this embodiment, the plurality of third bumps 177 may include an input terminal point and an output terminal point, and the plurality of third upper pins 154 may include an input terminal pin and an output terminal pin.

Please refer to FIG. 2 again, the plurality of upper pads 133 and 135 in each group G have a plurality of first side edges 1351 and a plurality of second side edges 1352 which are parallel to the reference line L and opposite to each other. The second upper pins 152 are respectively connected to the first side 1351 or the second side 1352 of the upper pads 135 arranged symmetrically on both sides of the reference line L. In detail, in this embodiment, the second upper pin 152 on the left side of the reference line L in each group G is connected to the first side 1351 of the corresponding upper pad 135, and the second side on the right side of the reference line L is the second The upper pins 152 are connected to the second sides 1352 of the corresponding upper pads 135, so that the upper pads 135 and the corresponding second upper pins 152 in each group G are arranged in a gate shape. In addition, in this embodiment, the second upper pin 152 is also corresponding to the first side 1351 or the second side 1352 connected to the upper pad 133, but the present invention is not limited thereto.

Please continue to refer to FIG. 2, the plurality of upper pads 133 and 135 in each group G are located farthest from the reference line L and are respectively located between two second upper pins 152 on both sides of the reference line L. In detail, in this embodiment, the plurality of upper pads 133 and 135 in each group G are located at the second upper pin 152 and the connection reference of the first side 1351 of the upper pad 135 on the left side of the reference line L. Between the second upper pins 152 of the second side 1352 of the upper pad 135 on the right side of the line L. In other words, each group G defines the layout space by the two outermost two upper pins 152 on both sides, and all the upper pads 133 and 135 and the other second upper pins 152 of each group G are arranged in the layout space one by one. The layers are arranged closely to make effective use of the layout space.

Please refer to FIG. 1 and FIG. 2 again. In this embodiment, the total area of the plurality of upper pads 133 and 135 in each row of each group G is determined by the innermost row R _i closest to the second inner end 127. _Ro gradually increases toward the outermost row away from the second inboard end 127. In detail, the pad 133 is located at the inner area of the upper row R _i is smaller than the outermost row of contact pads 135 on the total area of the plurality of R _o. It can also be said that the width of the upper pads 133 located in the innermost row R _i is smaller than the total width of the plurality of upper pads 135 located in the outermost row _Ro . The pads 133 and 135 are arranged in a shape close to an inverted triangle shape.

As a result, the plurality of upper pads 133 and 135 in the wafer bonding area 110 increase in a row and / or a total area / a total width in a direction away from the second inner end 127, and respectively pass through the corresponding first conduction. The hole 160 is electrically connected to the lower pin 156 on the lower surface 108 of the flexible substrate 200 without occupying the surface of the flexible substrate 200 outside the wafer bonding area 110 for wiring, and does not cause the second The pitch of the inner ends 127 is increased.

Therefore, the thin-film flip-chip packaging structure 10 of this embodiment uses the space in the wafer bonding area 110 to arrange the second upper pin 152, and connects the upper surface 106 and the lower surface 108 of the flexible substrate 200 through the first via 160. The second upper pin 152 and the lower pin 156, and then multiple upper pads 133 and 135 corresponding to the first via 160 are closely arranged in a grouped and layered manner, which effectively increases the pin foot Count and reduce the spacing between the pins. The second upper pin 152 is disposed in the wafer bonding region 110, which can further reduce the number of pins that are routed through the area outside the wafer bonding region 110, thereby increasing the flexibility of the circuit layout.

It is worth mentioning that in FIG. 1 and FIG. 2, one form of the circuit layer 300 is listed, but the form of the circuit layer 300 is not limited thereto. Other types of circuit layers will be described below.

4 to 6 are partial enlarged schematic diagrams of circuit layers of various thin-film flip-chip packaging structures according to other embodiments of the present invention. It should be noted that, in FIG. 4 to FIG. 6, the circuit layers 300 a, 300 b, and 300 c in different forms are taken as examples, but not limited thereto.

Please refer to FIG. 4 first. The main difference between the circuit layer 300a of FIG. 4 and the circuit layer 300 of FIG. 2 is that a plurality of pads 133a, 135a, 135a 'of each group G of the circuit layer 300a are arranged in more rows. As can be seen from FIG. 4, in this embodiment, the circuit layer 300 a has a plurality of second upper pins 152 a divided into a plurality of groups G (divided into two groups G only as shown schematically in FIG. 4). Each second upper pin 152a has a second inner terminal 127a and upper pads 133a, 135a, 135a '. The plurality of upper pads 133a, 135a, 135a 'in each group G are arranged in multiple rows one by one from the closest to the second inner end 127a and away from the second inner end 127a. Near each second inner end 127a, at least two rows of upper and lower pads 133a are provided on both sides of the single and asymmetric reference line L. A plurality of rows of upper contact pads 135a, 135a 'arranged symmetrically on both sides of the reference line L are provided in a direction away from the second inner end 127a. In this embodiment, the reference line L overlaps the center line of each group G.

In detail, the plurality of upper pads 133a, 135a, and 135a 'are located farthest from the reference line L and located between two second upper pins 152a on both sides of the reference line L, respectively. Each of the upper pads 133a, 135a, and 135a 'has a first side 1351a and a second side 1352a that are opposite and parallel to the reference line L. Each of the second upper pins 152a is connected to one of the corresponding upper pads 133a, 135a, and 135a ', respectively. In detail, in this embodiment, a plurality of second upper pins 152a located on the left side of the reference line L are connected to the first side edges 1351a of the corresponding upper pads 135a, and a plurality of second sides located on the right side of the reference line L The upper pin 152a is connected to the second side 1352a of the corresponding upper pad 135a, so that the upper pads 135a in each group G are arranged symmetrically on both sides of the reference line L in a face-to-face manner, and are in line with the corresponding second The upper pins 152a are arranged like a gate. Further, since each group G is the most remote from the mating end 127a of the second outermost row R _o has a maximum width may be provided on the pad, and therefore the present embodiment each group G is the outermost row R _o In addition to a pair of upper pads 135a symmetrically arranged face to face on both sides of the reference line L, a pair of upper pads 135a 'symmetrically arranged on both sides of the reference line L are included, and the upper pads on the left of the reference line L The pad 135a 'is connected to the second side 1352a by the corresponding second upper pin 152a, and the upper pad 135a' located on the right side of the reference line L is connected to the first side by the corresponding second upper pin 152a The edge 1351a is such that the upper pads 135a 'in each group G are arranged symmetrically on both sides of the reference line L in a back-to-back manner.

Please continue to refer to FIG. 4. In this embodiment, the total area of the plurality of upper pads 133a, 135a, and 135a 'in each row of each group G is from the innermost row R _i closest to the second inscribed end 127a to away from the second end of the contact 127a of the outermost row R _o gradually expanded. Therefore, the plurality of upper pads 133a, 135a, and 135a 'of each group G are arranged in a shape close to an inverted triangle shape in a plan view.

As can be seen from FIG. 4, the plurality of first bumps 175 a joined to the plurality of first inner joint ends 122 a and the plurality of second bumps 176 a joined to the plurality of second inner joint ends 127 a are arranged in a single row, respectively. However, the present invention is not limited to this. Please refer to FIG. 5. The main difference between the circuit layer 300b of FIG. 5 and the circuit layer 300a of FIG. 4 is that in FIG. 5, the plurality of first bumps 175b and the plurality of second bumps 176b in this embodiment are respectively along The direction parallel to the first side 173 (refer to FIG. 1) of the wafer 170 is arranged in at least two rows, and the second bumps 176 b of the at least two rows are farther away from the first side 173 than the first bumps 175 b of the at least two rows. The first bumps 175b in two adjacent rows and the second bumps 176b in two adjacent rows are staggered, respectively. Accordingly, the plurality of first internal connection ends 122b of the circuit layer 300b are correspondingly bonded to the plurality of first bumps 175b and the plurality of second internal connection ends 127b are correspondingly coupled to the plurality of second bumps 176b. Therefore, the plurality of first internal connection ends 122b and the plurality of second internal connection ends 127b are also arranged in at least two rows along the direction parallel to the first side 112 (refer to FIG. 1) of the wafer bonding area 110, and The plurality of first internal connection ends 122b in the adjacent two rows and the plurality of second internal connection ends 127b in the adjacent two rows are staggered, respectively. As can be seen from FIG. 5, the present invention can provide more fine pitches between pins, effectively reduce the pitch, and increase the number of pins by using multiple rows of staggered bumps and internal terminals.

Alternatively, the form of the circuit layer may be as shown in FIG. 6. The main difference between the circuit layer 300c of FIG. 6 and the circuit layer 300b of FIG. 5 is that a plurality of pads 133c, 133c ', 135c, and 135c' of each group G of the circuit layer 300c are arranged in more rows. In addition, in FIG. 5, is located away from the second end 127b connected to the outermost row furthest R _o is provided with a pair of symmetrically arranged in a face to face on both sides of the reference line L and a pair of pads 135b to The back pads 135b ′ are symmetrically arranged on both sides of the reference line L. In FIG. 6, the outermost row R _o wiring layer 300c is provided in each group G are two pairs of face to face relationship to the reference line L1 are arranged symmetrically on both sides of the pad 135c, that is, positioned left of the reference line L1 a second connecting pin 152c are positioned on the outermost row R _o corresponding to a first side of the pad 1351c 135c, and the reference line L1 is located on the right side of second connector pins 152c are positioned corresponding to the outermost row R _o The second side 1352c of the upper pad 135c. In addition, on the penultimate row R _m (that is, the outermost row _{Ro is} inward), there is still a surplus after a pair of upper pads 135c arranged symmetrically on both sides of the reference line L1 in a face-to-face manner. Space, so a separate upper pad 133c 'can be provided. The corresponding second upper pin 152c may not be connected to the first side 1351c and the second side 1352c of the upper pad 133c ', but connected to the center of the upper pad 133c'. Furthermore, in FIG. 6, a plurality of rows of symmetrically arranged upper pads 135 c and 135 c ′ may be symmetrically arranged on both sides of different reference lines L1 and L2. In the present embodiment, the outermost row located at the penultimate row R _o and R _m is the pad 135c located on both sides of the reference line L1, which overlaps the reference line L1 to the line of each group G. The upper pads 135c ′ located in the third and fourth rows are symmetrically arranged on both sides of the reference line L2, where the reference line L2 is adjacent to but slightly deviates from the center line of each group G. However, the present invention does not limit the number of different reference lines in each group. The above is only the form of providing several circuit layers, and the shape and arrangement of the circuit layers are not limited by the above.

FIG. 7 is a schematic partial cross-sectional view of a thin-film flip-chip packaging structure according to another embodiment of the present invention. Please refer to FIG. 7. The main difference between the thin-film flip-chip packaging structure 10 'of FIG. 7 and the thin-film flip-chip packaging structure 10 of FIG. 1 is that in this embodiment, the circuit layer of the thin-film flip-chip packaging structure 10' further includes The plurality of second via holes 165 of the flexible substrate 200 '. The plurality of second vias 165 are far from the wafer bonding area 110 and are respectively connected to the plurality of lower pins 156 '. In this embodiment, the plurality of second via holes 165 are adjacent to the first end 102 ′, and the plurality of lower pins 156 ′ are guided to the upper surface 106 ′ through the second via holes 165, and then connected to the upper surface 106 ′. The external pin 158 is used as an external electrical connection. Thereby, the final external connection portions of the first upper pin 150 'and the second upper pin 152' which are respectively bonded to the first bump 175 'and the second bump 176' can be located on the same surface (i.e., the upper Surface 106 '). Therefore, when the thin-film flip-chip packaging structure 10 'is connected to an external component (not shown), only the upper surface 106' of the thin-film flip-chip packaging structure 10 'can be electrically connected to the external components, which simplifies the way of external connection. However, the present invention does not limit the position of the external connection portion of the pin.

Please refer to FIG. 1, FIG. 3 and FIG. 7 together, the present invention may further include solder resist layers SR, SR 'and encapsulants 180, 180'. The solder resist layers SR, SR 'are disposed on the upper surfaces 106, 106' and the lower surfaces 108, 108 ', and completely or partially cover the first upper pins 150, 150', the third upper pins 154, 154 ', and Lower pins 156, 156 '. The solder resist layers SR, SR 'have an opening respectively to expose the wafer bonding area 110, that is, the solder resist layers SR, SR' will expose the first internal terminals 122, 122 'and the second upper pins 152, 152'. In addition, the solder resist layers SR, SR 'also expose the external connection portions of the pins. The encapsulants 180 and 180 'are filled at least between the flexible circuit substrates 100 and 100' and the chips 170 and 170 'to protect the electrical contacts between the circuit layer and the bumps. In addition, the above is only a form of providing several thin-film flip-chip packaging structures, and the manner in which the flexible circuit substrate is bonded to the chip is not limited to the above.

In summary, the thin-film flip-chip packaging structure of the present invention is configured by arranging a plurality of second upper pins having a second inner terminal and an upper pad in a wafer bonding area. These second upper pins are divided into a plurality of Groups, and multiple upper pads in each group are closely arranged layer-by-layer / row-by-row in a direction away from the second internal connection end to arrange more upper pads in a wafer bonding area of a limited size. Further, the upper pad and the lower pin are correspondingly connected through the first via hole, so that the flexible circuit board has a first upper pin extending outward from the upper surface of the flexible substrate, and also has chip bonding. The circuit extends to the second upper pin on the lower surface of the flexible substrate through the upper pad and the first via, and the second upper pin further extends outward through the lower pin. In this way, the number of pins that can be laid on the flexible circuit substrate can be greatly increased for chip connections with more bumps. Moreover, in the above configuration, since the upper pad and the second upper pin are in the wafer bonding area, the portion of the flexible substrate outside the wafer bonding area will not be occupied, and the wiring layer is on the flexible base. The layout on the wood can be more flexible.

Although the present invention has been disclosed as above with the examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some modifications and retouching without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application.

10, 10’‧‧‧ thin-film flip-chip packaging structure

100, 100’‧‧‧ flexible circuit board

102、102’‧‧‧first end

104、104’‧‧‧Second end

106, 106’‧‧‧ upper surface

108, 108’‧‧‧ lower surface

110‧‧‧ Wafer Land

112‧‧‧First side

114‧‧‧Second side

122, 122a, 122b, 122c, 122 ’‧‧‧ first internal end

127, 127a, 127b, 127c, 127’‧‧‧Second Inner End

133, 133a, 133b, 133c, 133c ’, 133’, 135, 135a, 135a ’, 135b, 135b’, 135c, 135c ’, 135’‧‧‧

137, 137’‧‧‧ under pad

1351, 1351a, 1351b, 1351c‧‧‧ First side

1352, 1352a, 1352b, 1352c‧‧‧ Second side

145, 145’‧‧‧ the third internal end

150, 150a, 150b, 150c, 150’‧‧‧‧ the first upper pin

152, 152a, 152b, 152c, 152’‧‧‧ second upper pin

154, 154’‧‧‧ third upper pin

156, 156’‧‧‧ under pins

158‧‧‧outer pin

160, 160a, 160b, 160c, 160’‧‧‧first via

165‧‧‧second via

170, 170’‧‧‧ chips

173‧‧‧first side

174‧‧‧second side

175, 175a, 175b, 175c, 175’‧‧‧ first bump

176, 176a, 176b, 176c, 176’‧‧‧ second bump

177, 177’‧‧‧ third bump

180, 180’‧‧‧ encapsulated colloid

200, 200’‧‧‧ flexible substrate

300, 300a, 300b, 300c‧‧‧ Line layer

G‧‧‧Group

L, L1, L2‧‧‧ reference line

R _i ‧‧‧ innermost row

R _m ‧‧‧ penultimate row

R _o ‧‧‧ Outer row

SR, SR’‧‧‧ solder mask

FIG. 1 is a schematic diagram of a thin-film flip-chip packaging structure according to an embodiment of the present invention. FIG. 2 is a partially enlarged schematic view of a circuit layer of the thin-film flip-chip packaging structure of FIG. 1. FIG. 3 is a schematic partial cross-sectional view of the thin-film flip-chip packaging structure of FIG. 1. 4 to 6 are partial enlarged schematic diagrams of circuit layers of various thin-film flip-chip packaging structures according to other embodiments of the present invention. FIG. 7 is a schematic partial cross-sectional view of a thin-film flip-chip packaging structure according to another embodiment of the present invention.

Claims (10)

A thin-film flip-chip packaging structure includes: a flexible circuit substrate including a flexible substrate and a circuit layer, the flexible substrate having opposite upper and lower surfaces, wherein the upper surface defines a wafer bond Area, the wafer bonding area has a first side and a second side opposite to each other, and the circuit layer includes: a plurality of first upper pins on the upper surface, each of the first upper pins having a first inner pin Terminals, the plurality of first internal terminals are located in the wafer bonding area and are adjacent to the first side, and each of the first upper pins is farther away from the wafer bonding area from the first internal terminal. A plurality of second upper pins are located on the upper surface and disposed in the wafer bonding area, and each of the second upper pins has an opposite second inner end and an upper pad, and A plurality of second internal terminals is adjacent to the first side and is farther from the first side than the plurality of first internal terminals, and each of the second upper pins runs from the second internal terminal to the first side; The direction of the second side extends to connect the upper pads, and the width of each of the upper pads is larger than that of each of the second pads. The width of other portions of the pins, the plurality of second upper pins are divided into a plurality of groups, and the plurality of upper pads in each group are from the vicinity of the second internal end toward the The direction of the second side is arranged layer by layer into at least two rows, and at least one row furthest from the second inscribed end has at least two of the upper pads arranged symmetrically on both sides of the reference line of each group, Wherein, the reference line is adjacent to or overlaps the center line of each group; a plurality of first via holes penetrate the flexible substrate and are located in the wafer bonding area, and the plurality of first via holes respectively correspond to Connected to the plurality of upper pads; and a plurality of lower pins located on the lower surface and electrically connected to the plurality of second upper pins through the plurality of first vias; and a chip having opposite A first side and a second side, and includes a plurality of first bumps and a plurality of second bumps close to the first side, the wafer is disposed in the wafer bonding area, and the plurality of first A bump is bonded to the plurality of first inscribed ends, and the plurality of second bumps are bonded to the plurality of second inscribed ends. . The thin-film flip-chip packaging structure according to item 1 of the scope of patent application, wherein each of the plurality of upper pads in each group has a first side and a second side that are parallel to the reference line and opposite to each other. The plurality of second upper pins are correspondingly connected to the first side or the second side of at least two of the upper pads arranged symmetrically on both sides of the reference line. The thin-film flip-chip packaging structure according to item 1 of the scope of patent application, wherein the plurality of upper pads in each group are located at two locations farthest from the reference line and located at two sides of the reference line, respectively. Said between the second upper pins. The thin-film flip-chip packaging structure according to item 1 of the scope of patent application, wherein the total area of the plurality of upper pads in each row of each group is farther away from the innermost row closest to the second inner end. The outermost row of the second inscribed end gradually increases. The thin-film flip-chip packaging structure according to item 1 of the scope of patent application, wherein the plurality of second bumps are arranged in at least two rows along a direction parallel to the first side, and the plurality of adjacent two rows The second bumps are staggered. The thin-film flip-chip packaging structure according to item 1 of the scope of patent application, wherein the circuit layer includes a plurality of third upper pins on the upper surface, and each of the third upper pins has a third internal connection end. The plurality of third internal connection ends are located in the wafer bonding area and adjacent to the second side, and each of the third upper pins is away from the third internal connection end in a direction away from the wafer bonding area; In an extension, the wafer includes a plurality of third bumps near the second side, and the plurality of third bumps are bonded to the plurality of third internal connection ends. According to the thin-film flip-chip packaging structure according to item 1 of the scope of the patent application, wherein each of the lower pins has a lower pad, the plurality of lower pads are respectively disposed corresponding to the plurality of upper pads, and each of the The lower pins extend outward from the lower pads, and the plurality of first vias are respectively correspondingly connected to the plurality of upper pads and the plurality of lower pads. The thin-film flip-chip packaging structure according to item 7 of the patent application scope, wherein the flexible substrate has a first end and a second end opposite to each other, the plurality of first upper pins and the plurality of The lower pins extend to the first end. The thin-film flip-chip packaging structure according to item 8 of the patent application scope, wherein the circuit layer includes a plurality of second vias penetrating through the flexible substrate, and the plurality of second vias are far from the wafer The bonding areas are respectively connected to the plurality of lower pins. According to the thin-film flip-chip packaging structure described in item 7 of the scope of the patent application, wherein the plurality of lower pins are respectively disposed corresponding to the plurality of second upper pins and the plurality of first upper pins.